Tasmanian Devil
The Tasmanian devil (Sarcophilus harrisii) is a carnivorous marsupial of the family Dasyuridae, now found in the wild only on the Australian island state of Tasmania. The size of a small dog, it became the largest carnivorous marsupial in the world following the extinction of the thylacine in 1936. It is characterised by its stocky and muscular build, black fur, pungent odour, extremely loud and disturbing screech, keen sense of smell, and ferocity when feeding. The Tasmanian devil's large head and neck allow it to generate the strongest bite per unit body mass of any living mammal, and it hunts prey and scavenges carrion as well as eating household products if humans are living nearby. Although it is usually solitary, it sometimes eats with other devils and defecates in a communal location. Unlike most other dasyurids, the devil thermoregulates effectively and is active during the middle of the day without overheating. Despite its rotund appearance, the devil is capable of surprising speed and endurance, and can climb trees and swim across rivers. It is believed that ancient marsupials migrated from what is now South America to Australia tens of millions of years ago during the time of Gondwana, and that they evolved as Australia became more arid. Fossils of species similar to modern devils have been found, but it is not known whether they were ancestors of the contemporary species, or whether the current devils co-existed with these species. The date that the Tasmanian devil disappeared from the Australian mainland is unclear; most evidence suggests they had contracted to three relict populations around 3000 years ago. A tooth found in Augusta, Western Australia has been dated to 430 years ago, but archaeologist Oliver Brown disputes this and considers the devil's mainland extinction to have occurred around 3000 years ago.[2] This disappearance is usually blamed on dingoes, which are absent from Tasmania. Because they were seen as a threat to livestock and animals that humans hunted for fur in Tasmania, devils were hunted and became endangered. In 1941, the devils, which were originally seen as implacably vicious, became officially protected. Since then, scientists have contended that earlier concerns that the devils were the most significant threat to livestock were overestimated and misplaced. Devils are not monogamous, and their reproductive process is very robust and competitive. Males fight one another for the females, and then guard their partners to prevent female infidelity. Females can ovulate three times in as many weeks during the mating season, and 80% of two-year-old females are seen to be pregnant during the annual mating season. Females average four breeding seasons in their life and give birth to 20–30 live young after three weeks' gestation. The newborn are pink, lack fur, have indistinct facial features and weigh around 0.20 g (0.0071 oz) at birth. As there are only four nipples in the pouch, competition is fierce and few newborns survive. The young grow rapidly and are ejected from the pouch after around 100 days, weighing roughly 200 g (7.1 oz). The young become independent after around nine months, so the female spends most of her year in activities related to childbirth and rearing. Since the late 1990s, devil facial tumour disease has drastically reduced the devil population and now threatens the survival of the species, which in 2008 was declared to be endangered. Programs are currently being undertaken by the Government of Tasmania to reduce the impact of the disease, including an initiative to build up a group of healthy devils in captivity, isolated from the disease. While the thylacine was extant, it preyed on the devil, which targeted young and unattended thylacine cubs in their dens. Nowadays, the devil is also preyed upon by the illegally introduced red fox, and localised populations of devils have also been severely reduced by collisions with motor vehicles, particularly when they are eating roadkill themselves. The devil is an iconic symbol of Tasmania and many organisations, groups and products associated with the state use the animal in their logos. It is seen as an important attractor of tourists to Tasmania and has come to worldwide attention through the Looney Tunes character of the same name. Due to export restrictions and the failure of overseas devils to breed, there are almost no devils outside Australia except for any that have been illegally smuggled Description The Tasmanian devil is the largest surviving carnivorous marsupial in Australia. It has a squat, thick build, with a large head and a tail which is about half its body length. Unusually for a marsupial, its forelegs are slightly longer than its hind legs, and devils can run up to 13 km/h (8.1 mph) for short distances. The fur is usually black, often with irregular white patches on the chest and rump (although approximately 16% of wild devils do not have white patches).[32][33] These markings suggest that the devil is most active at dawn and dusk, and they are thought to draw biting attacks toward less important areas of the body, as fighting between devils often leads to a concentration of scars in that region.[33] Males are usually larger than females, having an average head and body length of 652 mm (25.7 in), a 258 mm (10.2 in) tail and an average weight of 8 kg (18 lb). Females have an average head and body length of 570 mm (22 in), a 244 mm (9.6 in) tail and an average weight of 6 kg (13 lb),[32] although devils in western Tasmania tend to be smaller.[34] Devils have five long toes on their forefeet, four pointing to the front and one coming out from the side, which gives the devil the ability to hold food. The hind feet have four toes, and the devils have non-retractable claws.[30] The stocky devils have a relatively low centre of mass.[35] Devils are fully grown at two years of age,[29] and few devils live longer than five years old in the wild.[36] The devil stores body fat in its tail, and healthy devils have fat tails.[37] The tail is largely non-prehensile and is important to its physiology, social behaviour and locomotion. It acts as a counterbalance to aid stability when the devil is moving quickly.[38] An ano-genital scent gland at the base of its tail is used to mark the ground behind the animal with its strong, pungent scent.[39] The male has external testes in a pouch-like structure formed by lateral ventrocrural folds of the abdomen, which partially hides and protects them. The testes are subovoid in shape and the mean dimensions of 30 testes of adult males was 3.17 ×2.57 cm (1.25 ×1.01 in).[40] The female's pouch opens backwards, and is present throughout its life, unlike some other dasyurids.[40] The Tasmanian devil has an exceptionally strong bite for its size, generating a force of over 553 N (1,220 lb).[41] The jaw can open to 75–80 degrees, allowing the devil to generate the large amount of power to tear meat and crush bones[38] – sufficient force to allow it to bite through thick metal wire.[42] The power of the jaws is in part due to its comparatively large head. The teeth and jaws of Tasmanian devils resemble those of hyenas, an example of convergent evolution.[43][44] Dasyurid teeth resemble those of primitive marsupials. Like all dasyurids, the devil has prominent canines and cheek teeth. It has three pairs of lower incisors and four pairs of upper incisors. These are located at the top of the front of the devil's mouth.[45] Like dogs, it has 42 teeth, which are not replaced after birth but grow continuously throughout life at a slow rate.[37][44] It has a "highly carnivorous dentition and trophic adaptations for bone consumption".[46] The devil has long claws that allow it to dig burrows and seek subterranean food easily and grip prey or mates strongly.[44] The teeth and claw strength allow the devil to attack wombats up to 30 kg (66 lb) in weight.[46] The large neck and forebody that give the devil its strength also cause this strength to be biased towards the front half of the body; the lopsided, awkward, shuffling gait of the devil is attributed to this.[47] The devil has long whiskers on its face and in clumps on the top of the head. These help the devil locate prey when foraging in the dark, and aid in detecting when other devils are close during feeding.[44] The whiskers can extend from the tip of the chin to the rear of the jaw and can cover the span of its shoulder.[44] Hearing is its dominant sense, and it also has an excellent sense of smell, which has a range of 1 kilometre (0.6 mi).[37][44] The devil, unlike other marsupials, has a "well-deﬁned, saddle-shaped ectotympanic".[48] Since devils hunt at night, their vision seems to be strongest in black and white. In these conditions they can detect moving objects readily, but have difficulty seeing stationary objects.[37] Category:Animals Category:Mammals Category:Marsupials Category:Carnivores Category:Vertebrates Category:Australian Animals Category:Island Animals Category:Vertebrates Category:Forest animals